Sealing devices are used in well bores to seal the annulus between the well casing and a tubular, such as a production tube passing through the well bore. Conventional devices, such as packers, come in a number of types. Two of the most widely used types are inflatable packers and compressed element packers. In these packers, the seal is created by the application of pressure through the sealing element. One of the drawbacks of these types of packers is that enough pressure has to be applied during the setting of the packer to make a seal strong enough to withstand all the forces that will be applied to the seal during use
A cup seal packer, of the type described in the applicant's co-pending European Patent Application EP1503031 overcomes some of the drawbacks of conventional packers by providing a cup seal which requires only sufficient load be applied to form an initial contact seal with the well casing. The cup seal packer is self-energising by using well pressure to make the seal with the well casing. One of the drawbacks of a cup seal packer of this type, however, is they can only safely hold pressure from one direction. To overcome this drawback, if it is required to provide sealing from above and below two cup seals are used, the cups facing in opposite directions.